Adolescents in under-served, urban communities are disproportionately involved in the juvenile justice system. This early engagement has been shown to be a strong predictor of more serious offenses in adulthood, such that youth involvement in the court system is a significant public health concern. Juvenile justice approaches have traditionally emphasized individualized treatment efforts combined with discipline and punishment. More recently, however, juvenile justice professionals have questioned the adequacy of this approach and are increasingly adopting an asset-based perspective referred to as "positive youth justice" (PYJ). The PYJ approach encourages youth court participants to build upon their existing strengths, while learning and mastering new life skills, through development of pro-social relationships within their peer group, family, and community. These "core assets" are posited to promote the successful entry into young adulthood. For this project, the investigative team will adapt and test a multilevel, multi-component, intervention that has strong potential to reduce substance use and delinquency while correspondingly promoting positive youth justice among youth court participants and staff. The first component of the current project involves interviewing program directors from a representative sample of youth courts throughout the U.S to gain formative feedback about logistical and programming concerns. The second component of the project is designed to promote individual-level change among youth participants and consists of an adapted version of the Life Skills Training (LST) program, an evidence-based drug and violence prevention program which teaches personal self-management skills, social skills, drug refusal skills, and other life skills needed to successfully navigate developmental tasks, increase resilience, and facilitate healthy psycho-social development. Several youth courts have used the Life Skills Training program, suggesting that it meets a perceived need and is feasible in this setting. However, LST has never been rigorously tested in the youth court setting. The proposed research will involve a randomized efficacy trial with 560 adolescents in youth court. The investigative team will examine intervention effects on substance use, delinquent behavior, school performance, and recidivism rates using mixed qualitative (assessment of dosage, fidelity, and provider and participant feedback to determine their impact on program efficacy) and quantitative (survey assessments at pretest, post-test, and six-month follow-up) methods to estimate the effect size of the adapted and combined program. By intervening with both youth court participants and youth court staff, the proposed multilevel intervention can have a broad impact on risk and protective factors at multiple levels of influence. The ultimate goal of this research is to promote the use of an evidence-based prevention approach adapted specifically for implementation in youth courts in order to reduce the adverse consequences of drug abuse, violence, and delinquency among youth offenders.